ci: sync with libbpf/ci@v3

* vmtest.yml
  * use v3 of libbpf/ci actions
  * remove unnecessary selftests preparation steps
* ci/vmtest
  * remove unnecessary scripts and configs
  * add libbpf-specific run-vmtest.env [1]

[1] https://github.com/libbpf/ci/pull/166

Signed-off-by: Ihor Solodrai <ihor.solodrai@pm.me>

ci/vmtest/configs/run-vmtest.env

@@ -0,0 +1,37 @@
+#!/bin/bash
+
+# This file is sourced by libbpf/ci/run-vmtest Github Action scripts.
+
+# $SELFTESTS_BPF and $VMTEST_CONFIGS are set in the workflow, before
+# libbpf/ci/run-vmtest action is called
+# See .github/workflows/kernel-test.yml
+
+ALLOWLIST_FILES=(
+    "${SELFTESTS_BPF}/ALLOWLIST"
+    "${SELFTESTS_BPF}/ALLOWLIST.${ARCH}"
+    "${VMTEST_CONFIGS}/ALLOWLIST"
+    "${VMTEST_CONFIGS}/ALLOWLIST-${KERNEL}"
+    "${VMTEST_CONFIGS}/ALLOWLIST-${KERNEL}.${ARCH}"
+)
+
+DENYLIST_FILES=(
+    "${SELFTESTS_BPF}/DENYLIST"
+    "${SELFTESTS_BPF}/DENYLIST.${ARCH}"
+    "${VMTEST_CONFIGS}/DENYLIST"
+    "${VMTEST_CONFIGS}/DENYLIST-${KERNEL}"
+    "${VMTEST_CONFIGS}/DENYLIST-${KERNEL}.${ARCH}"
+)
+
+# Export pipe-separated strings, because bash doesn't support array export
+export SELFTESTS_BPF_ALLOWLIST_FILES=$(IFS="|"; echo "${ALLOWLIST_FILES[*]}")
+export SELFTESTS_BPF_DENYLIST_FILES=$(IFS="|"; echo "${DENYLIST_FILES[*]}")
+
+if [[ "${LLVM_VERSION}" -lt 18 ]]; then
+    echo "KERNEL_TEST=test_progs test_progs_no_alu32 test_maps test_verifier" >> $GITHUB_ENV
+else # all
+    echo "KERNEL_TEST=test_progs test_progs_cpuv4 test_progs_no_alu32 test_maps test_verifier" >> $GITHUB_ENV
+fi
+
+echo "cp -R ${SELFTESTS_BPF} ${GITHUB_WORKSPACE}/selftests"
+mkdir -p "${GITHUB_WORKSPACE}/selftests"
+cp -R "${SELFTESTS_BPF}" "${GITHUB_WORKSPACE}/selftests"